Gun



GUN

Filed March 19, 1955 6 Sheets-Sheet l Jan. 14, 1.936. D. M. WILLIAMS GUN 6 Sheets-Sheet 3 Wd /l Wzlluuns fJf/ fluo/ww Filed March 19, 1935 Jan. 14, 1936. D. M. WILLIAMS Filed Maron 19, 1935 6 Sheets-Sheet 5 Jan.14,1936. y b. M. WILLIAMS 2,027,892l

GUN

Filed March 19, 1955 6 Sheets-Sheet 6 Patented Jan. 14, 1936 e i i ,i i 2,027,892;

i 'UNVIIEID` STATESl PATENT OFFICE 'c "l vv2,027,392 i v GUN pavia M. williams, Godwin, N. o. Application March 1s, 1935, serial No. 11,819

'- 34 Claims. (elysa-3) The present invention relates to guns, and weight and construction that requires calibre .30 especially machineguns. 1906 Govt. cartridges for operation, may be op- The presentl day military machine guns, as erated, in accordance with the present invention, usually designed, have such weight and their with low intensity cartridges having bullets of 5 parts are S0 constructed as to require high inlarger diameters, such as the .45` automatic pistolV tensity ammunition to operate the same. cartridges that are used in the Government model By high intensity ammunition is meant ampiStol calibre .45. y munition which on tiring develops high pres- The above examples bring out the fact that th sure, `and imparts to the bullet or projectile high calibre1 of the bullet iS not the determining factor l0 lvelocity and great striking energy. Itis a charinvolved in the present invention, but that the lo acteristic of high intensity ammunition that it determining factor iS that machine guns requirdevelops a high kinetic energy. ing anammunition developing a high recoil can In accordance with the present invention, mabe operated With ammunition developing a. W chine guns Wmeliwould ngrmally require high recoil. It is, of course, quite evident that the l5, intensity ammunition to operate the saine are recoil in effect depends upon Whether the ce!" 'l5 operated' by lowintensity ammunition. tridge iS a liigli intensity cartridge or lowin- By low intensity ammunition" is meant amtenSlty cartridgev munition which possesses low ballistic properties. In accordance With the present Invention, When High intensity military ammunition generally using low intensity ammunition, a portion of the 2o speaking, designates oridentifles ammunition of 10W pressure gases produced by firing of `the cer- 20 which the bullet is of large calibre but as the term tridgeS ree-cts upon the Pressure area 0f movhlgh intensity" is used in the present specifica. able member, hereinafter termed the actuator, tion, it does not necessarily mean that the bullet to thereby increase the kinetic effect of the gases. -is of large calibre. The bullet may be of smelll` In other words, the'operation of the gun, irrespecdiameter or calibre and the cartridge be of such tive of Whether it iS a recoil operatedgun or gesv Q5 a character as to develop the high pressure and operated gun, is effected by having 10W Pressure the high velocity which characterizes the high gases generated by 10W intensity ammunition actintensity ammunition. In other words, even .ing upon 8 certain predetermined Pressure area though the calibre of the bullet may be small, of'the movable member, and thisv area may be the high intensity ammunition has high ballisi-,lcf made smaller or larger inorder to decrease or in- 3g properties. It follows, therefromthat ythe term `A crease the operating force. In other Words. low intensity ammunition as used in the pres` broadly, in accordance With the present invenent specification does not necessarily refer to a tioni the energy Present in the 10W pressure geSeS cartridge having a bullet of any specific calibre; may be Vdistributed over a smaller or larger area :5,5 The calibre of the bullet may be large, relatively to generate a force Which iS Sllfcient `to operate 35 speaking, but the cartridge has low ballistic propparts of thegun which heretofore have only been erties. f operated by high pressure gases. One of the i VIn grder to illustrate more specically what is basic features of the present invention is that the meant in the presentspecication by the terms operating energy can be controlled by using a 40 fhigh intensity-ammunition" and low intensity constant gas pressure and Varying the pressure 40 ammunition andr to4 show' that these terms are area over which it acts or that the pressure area not limited to more specic diameter of the bullet, can be held constant, and the characteristics of the following examples are given: the cartridge controlled so the gas pressure geny A gun havingoperating parts, including breech erated upon ring the cartridge may be varied.

mechanism, of such f weight and construction The'present invention in one of its forms com- 45 which normally would have to be operated with prises the combination with a gun having a bolt calibre .30 1906 Govt. ammunition, may be opermechanism provided with` parts of large calibre erated, in accordance with the present invention, weight and resistance, but adapted to function by using a low calibre .22 rim re cartridge. with sub-calibre ammunition, with a sub-calibre In this case the bullet of the `cartridge which barrel for said gun, and a movable actuating 50 is used to operate, in accordance with the present member for said bolt mechanism including a gas invention, has a smaller diameter than the callchamber receiving the powder gases of combusbre .30 1906 Govt. cartridge. tion upon iring of the gun, said chamber having A further `example is as follows: a pressure area of such extent as to eiect opera- '55 A machine gun having mechanism of such tionof the boltmechanism upon firing o! the sub- 55 calibre ammunition in said gun. In one form 'of the invention, the actuating member for the bolt is mounted in telescopic relationship to the barrel and is arranged to form a gas chamber at the rear end of the barrel asit moves rearwardly thereof.

The invention is also broadly directed to a rearm having the usual bolt mechanism, ammunition chambering means, and an actuator in which means are provided, in addition to the usual cartridge chamber, for venting a part of the expanding gases, when the bolt member after firing of the firearm, has moved a predetermined distance rearwardly.

The actuating member has a sleeve extending forwardly from the rear portion thereof and tting slidably on the rear end ofthe barrel. This sleeve has gas venting means closed when the sleeve is in ammunition firing position and open upon the sleeve moving a predetermined distance rearwardly. A gas tight packing, which may be in the form of the ordinary piston ring, such as used on automobile pistons, is provided between the rear end of the machine gun barrel and the actuator sleeve.

It is also an object of the present invention to provide in a firearm having a bolt mechanism, means for actuating the bolt and ammunition chambering means cooperating with said members, a cartridge having the forward end of its powder case projecting therefrom, and means associated with the barrel oi' the firearm and the powder case chambering means to cause equalization of gas pressure within and without said projecting end of thepowder case. A

In the preferred form of the invention, the

- powder case projects Lforwardly of the cartridge chamber member and into the rear end of the barrel, the latter being recessed to receive the projecting end of the powder case, the recess vhaving a chamfered peripheral wall to permit equalization of the gas pressure inside and outside of said projecting end.

The present invention also contemplates certain novel details of combination, construction and arrangement of parts of the improved machine gun, whereby certain important advantages are obtained as will be more-fully described hereinafter, and pointed out in the claims, it being understood that the invention issusceptible to various changes in construction which may be made within the scope of the claims, without departing from the spirit of the invention.

The present invention will be disclosed and fully explained by reference to the accompanying drawings, wherein:

Figure 1 is a longitudinal vertical section of a machine gun in its closed or ready-to-re position;

Figure 2 is a detail showing the muzzle end of the stationary barrel of the gun;

Figure 3 is a longitudinal vertical section of the machine gun in its fully opened position;

Figure 4 is an enlarged longitudinal vertical section of a portion of the machine gun mechanism showing the powder case and the relative position of the movable chamber means to the barrel when the gun is in its closed position substantially immediately after firing;

Figure 5-is a similar view showing the positions of said parts after the cartridge has been fired and has moved the gun mechanism to a partially retracted position;

Figure 6 is a similar view of the gun after firing showing the movable chamber means in its fully retracted position;

Figure '7 is an enlarged plan view showing the movable chamber means assembled with the extension member;

Figure is a longitudinal section of the movnion block I5, jacket I6, and cover I1 pivoted on pin I8.

The receiver is provided with the usual trigger I9, pivoted at 20,\said trigger cooperating with sear 2|, the sear 2| operating under the inuence of spring 22. As shown in Fig. 1, when the gun is in its ready to fire position, the sear 2| engages the notched portion of the striker 23, the latter being provided with striker' points 24 and 25.

'Ihe striker member 23 is brought into the ready to fire position by means of the cooking lever 26.

Located Within the bolt 21 are many of the parts above referred to, said bolt 21 being provided with a rearward portion 28 and a forward portion 29, which engages the rearward portion of the movable chamber 30 which is secured in any suitable manner, for example, by threads 3| to the extension member 32, said extension member being provided with grooves 33, one on each side of the extension member to receive the bolt 21.

Secured to the left hand side plate of the receiver isa depressor feed cam 34 (shown in detail in Fig. 10), provided with two cam surfaces 35 and 36 adapted to cam the depressor31, pivoted at 3B, downwardly on the forward stroke of the bolt 21, said depressor 31 being provided with a lug member 39 recessed to receive the depressor plunger 40 which is held against the left side plate II, by means of a spring- (not shown).

f The lug member 39 at its upper portion is provided with an upper cam surface 4I adapted on opening of the gun to engage the lower cam surface of covercam 42, as shown in Fig. 3; the cover cam serving to partially depress the depressor 31 on the opening movement of the gun. The depressor is further depressed on theclosing of the gun by means of the depressor plunger 40 cooperating with the cam surface 36. The depressor lug 39 is provided at its lower portion with a lower cam surface 43 adapted to depress the cartridge 44, as more fully described hereinafter, the dotted lines in Fig. 3 showing the cartridge 44 in its depressed position.

The depressor lug 39 is provided with a further cam surface 4Ia positioned adjacent to the cam surface 4I, the cam surface 4|a being below the cam surface 4|, as shown in Fig. 4.

The cover spring 45 engages the depressor cam surface 4Ia, as shown in Figs. 1 and 4, respectively, said spring causing the lower cam surface 43 to engage the cartridge 44 and push downwardly thereon, causing the shell head 41 to engage the extracting edge 48 of the extractor 46, 'which serves to extract the cartridge from the ammunition belt.

ttached to the side receiver plate is the cam 49 having a camming surface 56.

The actuator or movable member is identified as an entity by the numeral 39. This actuator comprises a rear portion 55 provided centrally thereof with a powder case chamber 5l, as shown acer-,89a

yator is a recessed member 52 having a wall 53 and a gas chamber- 54 connecting with the powder case chamber l but of much ,larger diameter. The wall 53 forms a sleeve'surrounding the rear end ofthe barrel 59, said' sleeve functioning as a bearing, support, or guide for the actuator and its associated parts. I At the rear end of the gas chamber 54, there is provided adjacent the powder case chamber 5I a gas contact or pressure area 56. l v

A portion of the gas chamber 54 is provided for the escape of the residual gases presentafter the ring of the cartridge. The exhaust of the residual gases also functionsvto vkeep the gas chamber free from any elements oli-combustion. Ifthese elements are present, there is a tendency for the actuator 36 to bind or'freezeftothe rear end of the barrel 59 vandthereby casemalfunction of the gun.

In the form of the invention ishownfin Figs. 8 and 9, the exhaustmeans comprise grooves 51 which are arranged 'conoentrical`ly'oi'A the axis r tactface 56. As shown inFig. 1, the barrel 59 iat its rearward end is xedly mounted in the of the gas chamber, 54,` the latterjasV` shown, being in the form of a cylinder.'- YIt'iswithin the province ofthe presentinventio'n to have the gas chamber 54 assume anygeometric form, the

` only limitation being Vthatlit must'havethe same shape as the barrel memben When the gas chamber 54is 'a cylinder, the grooves 51 may be 4arrangei'i'- concentrically of theaxisfof the cyl- 'The 'grooves 51 are merely illustrative ofone suitable form o f ythe means which may be used to allow the` escape* of the residual gases from the gas chamber-54. Although-the grooves have been -found most satisfactory, instead of using grooves, the wall y53 of the actuator 30 may be provided with holes or any other recess which alloivsthe residualgases ItdeScape at the `desired i"time"in'i'zerval during the loperation of the gun.

The exhaust means or gas venting means' is closed when the actuator L'sleeve is in the ammunition firing position, and open when the sleeve 'has moveda predetermined distance upon the rearward' ,strokel of the actuator.

The barrel 59 having a bore 66 isp'rovided at its rearend with a chamfer 6I leading into the bullet seat 62. The rear end rof the barrel has an annularvface 63 adapted 'in one of its positions to come in close contact with the gas consleeve 64. The muzzle end of the barrel is also stationarily mounted in the forward end of the jacket I6, vas shown in Fig. 2.

It is to be noted that the powder case 58 has `its front end 58a protruding beyond-the forward 60 end of the powder case chamber 5I and preferably, although not necessarily, intothe rear end of the barrel bore. u l

As shown in Fig. 4, the crimped end 58a of the powder case 58 extends into the chamfered por- "tion of the barrel bore. The chamfered portion allows the bullet 58h to enter the bullet seat 62 without shaving on any material, for example, lead or the like, from the bullet.

The protrusion of the powder case, as shown, causes the entire bullet to be placed into the barrel borebefore firing, and thereby prevents the shearing off or accumulation of any lead or other parts of the bullet on the rear end of the barrel when the cartridge is fired.

As shownin Fig. 4; the bullet has travelled a 'short distance in the barrel bore.

The chamfered bore further servesto allow .the gases topass around the front end 59a of the powderl case to impinge against the gas contact, area 56"and the annular face v63 of the rear end' of the barrel. The gases being free" to pass around the outside wall of the front of the powder case produces the same vpressure on theoutside wall as on the inside wall, thereby` neu-I tralizing the action of I the gases which would swell out the front end of the powder case.

The above construction provides means for preventing the front endof the powder case, which 'protrudes' beyond the gas contact wall, from cess or chamber 66. The exhaustgases and elements of combustion pass out ofi` the grooves atl the extreme forward ends thereof 'into the chamber 66, and the elements of combustion are dej posited at the forward end thereof.

In accordance with the above, the cylindrical member surrounds the barrel and sleeve in spaced relation thereto, the barrel being secured in its forward end, and the cylinder being open at its rear end. It is within the province of the present invention to change the shape of the cylinder, and in the claims, the term cylinder isto be given this broad interpretation.

lAt or near the rear end of the barrel 59 a piston ring 61 is tted, said piston ring serving as a gas seal. v y

' The operation; of the gun is as followsz:l

The gun is shown in its closed ready-to-lre position in Fig. 1. The pull on trigger l I9causes4 it to pivot on pin 20 and its forward end to pull -sear 2| downwardly, disengaging `the sear with striker 23.` The striker then moves forwardlyunder the influence yof spring 23a, causing the striker point.24 to iire the cartridge, as shown in Fig. 4. Fig. 4 also shows that when the cartridge is red, the gases escaping from the mouth of shell 58a will follow the rear end of chamfer 6| and come into contact with the rear face 63 of the barrel 59 and also with the gas contact face 56 of the actuator 30, as shown in Fig. 4. The pressure of the gases at this time is equal on the outside and inside of front end of powder case 58 at the crimped and adjacent portions 58a, preventing the bulging or swelling of the front end of the powder case. The gases acting on stationary face 63 of stationary barrel 59 and on gas contact face 56 in actuator 30 cause the actuator 30 to have a powerful or violent rearward movement. Different stagesA of this movement are shown in Figs. 5 and 6. As actuator 30 moves rearwardly, it carries extension 32, bo1tj21 and their associated parts rearwardly. 1 The depressor 31 acting under tension of spring 45 holds- .the cartridge 44 is extracted from belt 44a, the latter being shown in Fig. 1.

As shown in Fig. 5, thexactuator 30 and exhaust grooves 51 move to their respective positions relative to rear face 63 of barrel 59.v During vthis said short movement, the actuator 30 and rear end of grooves 51 come to a position indicated at the point 51a, the forward end 58a of the powder case B remaining in the powder case chamber 5 I. At these positions, the residual gases have begun to escape through .grooves 51 and into the barrel sleeve chamber 66. A continuation of this short movement is shown in Fig. 6. The -rear ends 51a of exhaust grooves 51 occupy their most rearward position, and the powder case 58 is extracted from the powder case chamber 5| When these parts are'in the respective positions above set forth, the exhaust of the residual gases and elements of combustion have been completed.

The actuator 30 having come to rest, the bolt 21 and its parts continue to move rearwardly under the inuence of the momentum gained through the movement of actuator 30. The bolt mechanism continues rearwardly, carrying with it the fired powder case 58 and live cartridge 44.

During this movement, the depressor 31 is .cammed downward by cam 42, forcing live cartridge with it, as shown in Fig. 3. (Fig. 5 shows the intermediate position of the cartridge in the depressor.)

Immediately before the bolt comes to the full o pen position, the striker 23 is moved to the cocked position by cooking lever 26 operating against top plate I3.

The gun is now at the end of its recoiling movement, or stated differently, it is in its opened position.

In the nal closing movement, the bolt contacts with actuator 30, driving it to the closed position. The depressor'plunger 40 contacting with cam face.50 of cam 49 raises the depressor 31 to its uppermost position. The closed positions of the operating parts, including the depressor 31, bolt 21 and actuator 30, are clearly shown in Figs. 1 and 4, respectively.

'I'he structure set forth, and especially the structure of the actuator 30 and the manner in which it cooperates with the gun mechanism enables, as pointed out, the operation with low intensity ammunition, of a machine gun which normally would require high intensity ammunition ballistically speaking. It has been discovered, in accordance with the present invention, that low intensity ammunition ballistically speaking be used to actuate a gun carrying operating parts which would normally require high intensity ammunition ballistically speaking, provided an actuator is used which is capable of multiplying the kinetic effect of the expanding gases produced by the firing of the cartridge.

It is desired to point out that the movable operating parts of large calibre machine guns In the closing or counter recoiling movement,

y -2,027,892 ly for a short distance. During this movement,

have a certain weight, and -these parts are required in operation to move with a certain force through a certain distance to facilitate the loadirm and unloading of the long large calibre ammunition.

In accordance with the present invention, these parts are operated by using low intensity ammunition ballistically speaking, which may be under some circumstances sub-calibre ammunition and utilizing the pressure generated by the ring of the cartridge to generate the required recoilingl effect, but having thergases act upon a certain contact area. This area is predetermined in accordance with all o1 the factors above set forth, namely,l the weight of the operating parts of the gun, the stroke of the'operating parts, the amount of resistance tobe overcome, including spring resistance and frictional resistance, and the speed desired. The following are actual examples of guns constructed in accordance with the present invention:

1. -A machine gun having operating parts weighing approximately 3 pounds, a bolt stroke of approximately 41A inches, and equipped with the regular calibre .30 springs, including the bolt driving spring, was caused to function satisfactorily by providing an actuator having a gas contact face 56 of .626 diameter, said gun being operated with regular low pressure calibre ,22 rin fire cartridges.

2. A machine gun having operating parts weighing approximately 41/2 pounds, a bolt stroke of approximately 41A inches, and equipped with regular calibre .30 springs, including the bolt driving spring, was caused to function satisfactorily by providing an actuator having'a gas contact face 56 of .875 diameter, Vsaid gun being operated with regular low pressure calibre .22 rim fire cartridges.

It is within the province of the present inven- ,tion to have the ammunition receiving chamber long enough to chamber the entire cartridge or it may be longer than the cartridge. In that case, of course, no means are necessary to cause equalization 'of the gas pressure, since the powder'case does not project out of the cartridge chamber.

It is also within the province of the present invention to use the structure set forth with high intensity ammunition wherever the structure will adapt itself to the use of such ammunition.

The term sub-calibre barrel as used in the present application and in the claims, denes a y barrel which is adapted to be used in conjunction with sub-calibre ammunition, as hereinbefore set forth.

As previously pointed out, a gun utilizing the present invention, can use .22 calibre rim fire cartridges. If the present invention was not embodied in the gun, and all the operating parts were of the same weight andl construction, there would be required calibre .30 1906'Govt ammunition, or its equivalent, to function the gun. This bringsout thepoint that in most cases, the diameter of the barrel bore will be sub-calibre to accommodate the smaller diameter bullet but as pointed out in the previous discussion, the diameter of the barrel bore can, under some circumstances, be larger.

A further example is as follows:

A machine gun havingmechanism of such weight and construction that requires calibre .30 1906 Govt cartridges for operation, may be operated, in accordance with the present invention, with low intensity cartridges having bullets of larger diameters, such` as the .45 automatic pistol cartridges that are used in the Government model pistol calibre .45.

v"lf'hisisanexampleof a'gunin l l eter lof the `barrel bore has beenV increased yfrom the diameter'wvhich .would be employed the present invention had not been'employed. l l i The present invention,l while of particular value when incorporated in machine guns, may be incorporated in various kinds of firearms. It is desired to further point out that the basic principle herein disclosed whereby a may be operated withlowintensity ammunition by employing a relatively large gas contact or pressure area, is disclosed in another form in my prior applications, Serial No. 514,252, led February 7, 1931, and Serial No. 686,932, filed Aug. 26, 1933, and it is stated insaid prior applications that the principle of utilizing a large gas contact kor pressure area may be used for .the operation of firearms in general. The present `'application is ofv similarly broad scope, and while yparticularly adapted for machine guns, is not limited thereto. The present application isa continuation-.impart of said prior applications. y Y It is desired to pointl out that the arrangement set forth insaid prior application enables agun having yoperating parts, including breechy mechanism,` of such `weight and construction, which normally would have to be operated withA calibre .3o 1906 Govt. ammunition, to be, operatedwby" usinglowintensity ammunition, which-may be a rlm fire cartridge,y or it maybe a cartridge such as a, .45 automatic `pistol cartridge that is used in the Governmentmodel -pistol.45. v

While the present. invention has beendescribed in., connection with the gun villustrated in the drawings, it isrecognize'd that it can be used in connection withv all conventional types ofgmat chine guns' including those,` usually known under the terms gas operatedmachine guns and recoil operated machine guns. Such changes as are necessary are within the province of the ordinary-worker skilled in the gun art.

The` present application and the specific arrangements therein disclosed may incorporatethe principles set forth in the prior application. l

1. In a machine gun having'breech mechanism and ammunition feedingmeansv of such `weight andresistance as to normally require high intensity ammunition to operate the same; the com-v bination. of a stationary barrel, bolt means-fincluding a bolt, a reciprocating'actuator provided with means for chambering a low intensity carf-tridge and a gas chamber. member, said actuator Shaving a gas chamber formed therein communimined distance rearwardly, a gas contact area in saidv gas chamber to initiate movement of the actuator under the infiuerice of the gas, the actuator initiating rearward movement o f the bolt,

the area of said gas contact surface being `predetermined in accordance with the resistance of the moving `parts of the gun, the force required to function said masses, andthe working pressure generated by saidy low intensity cartridge so that when `the said cartridge is fired, the explosion which the diammoving parts and function said moving parts as lsatisfactorily as if high intensity ammunition wereused.' c l. 2. Ina machine gun having breech mechanism designed to yresist `,and operate under the explosive force' developed by a'cartridgejor said gun of` normal calibre and explosive intensity; thecom vbination of albarrel having a sub-calibre'bore, bolt means including za bolt, a reciprocating actuator provided with meansfor chambering a subcalibre cartridge nf equal calibre with said subcalibre barreLsaid cartridge developing explosive gases -of lowerv than normal intensity, `said actuatorbeing provided with a gas chamber member and having a gas chamber formed therein communicating with said cartridge chambering means, said gas chambermember being mounted in telescopic relationshipl withsfthe rear portion of the barrel, agas contactlzareain said gas of the actuator underthe inue'nce ofthe ex-` plosionl gases, :said actuator initiating v rearward movement ofthe-bolt, the area of said gas contact surface being predetermined in. accordance with-fthe resistance of. the moving parts ofthe gun, the force required to function said masses and the Working pressure generated by said subcalibrezcartridge, so that when the said cartridge isred, the explosiongaseswillreact against said area to produce a force suflicient to overcome the resistance off the moving parts and function-said moving parts-as satisfactorily as if a cartridge of normal calibre and normal explosive intensity vwerevused. 'w r 3. The combination with a firearm having bolt mechanism including ra. bolt; and a barrel, of means for effecting operation of `said bolt mechanism upon the firing of the ammunition, said means including-a movable actuator provided with a certain chamber, and means in addition to mounted in telescopic relation to said barrel land arranged to form a gas chamber at the rear end of the barrel, as it moves rearwardly of the barrel,and means in addition to the usual barrel bore to effect opening of said chamber to the atmosphere after a predetermined` rearward movement Aof the` actuating member is effected to `thereby exhaust the elements of combustion. 5. a-'gun ot the kind described having a bolta barrel, an` actuating member for the bolt arranged to form ai4 gas chamber as it moves rearwardly of thebarrel', and means in addition to the usual barrel bore to effect opening of said chamber to the atmosphere after'a predetermined rearward movement of the actuating member is effected to thereby exhaust the elements of com-v bustion; 'v f x 6. In agun'of the'kind described having a bolt, a barrel, an actuating member for the bolt mounted in telescopicrelation to said barrel and arrangedtol forma gas chamber at the rear end of the barrel yas it moves rearwardly ofthe barrel, means to effect `opening of said chamber to the atmosphere after a predetermined `rearward movement. of the actuating memberv is effected, and a cylinder having one end open and receiving the exhaust gases from said chamber to provide al space fdr depositing the elements of combustion. 7. In a gun of the kind described having a bolt, a barrel, an actuating member for the bolt arranged to form a gas chamber as it moves rearwardly of the barrel, means to eifect opening of said chamber to the atmosphere after a predetermined rearward movement of the actuating member is effected, and a cylinder having one end open and receiving the exhaust gases from said chamber to provide a space for depositing the elements of combustion. e

8. In a gun of the kind described, a barrel, and a bolt mechanism actuating member having a. rear end provided with a powder case chamber having a length shorter than the length of the powder case of the cartridge to be used therein, a cartridge with the forward end of its powder case projecting forwardly of said powder case chamber, and means associated with the barrel and actuating member arranged to" cause equalization of gas pressure within and without said projecting end of the powder case.

I 9. In a firearm having a bolt mechanism including a bolt, means for actuating said bolt, ammunition chambering means cooperating with said bolt and bolt operating means, said ammunition chambering'means including a powder case.

chamber having a length shorter than the length A of the powder case of the cartridge to be used therein, a cartridge with the forward end of its powder case projecting forwardly of said powder case chamber, and means associated with the barrel and the powder case chambering means arranged to cause equalization of gas pressure within and without said projecting end of the l powder case.

10. In a gun of the kind described, the combination with a barrel having a free rear end portion and bored for small calibre ammunition, an

said sleeve and barrel being arranged to prevent the escape of expanding gases resulting from the firing of ammunition until after the sleeve has moved a predetermined distance rearwardly and bolt mechanism actuated by the rearward motion of said actuating member.

11. In a gun of the kind described, the combination with a barrel having a free rear end portion and bored for small calibre ammunition, an actuating member including a rear portion bored to receive the powder case of such ammunition, said actuating member also having a sleeve extending forwardly from said rear portion and fitting slidably over the. rear end of said barrel, a gas-tight packing between the rear end of the barrel and said sleeve, and bolt mechanism actuated by the rearward motion of said actuating member.

12.`Inv a gun of the kind described, the combination with a barrel having a free rear end portion and bored forl small calibre ammunition, an actuating member including a rear portion bored to receive the powder case of such ammunition,

said actuating member also having a sleeve exsaid sleeve having gas venting means closed when the sleeve is in ammunition firing position, and open after the sleeve has moved a predetermined distance rearwardly, and bolt mechanism actu-l ated by the rearward motion of said actuating member.

1a. In a gun of the kind aeseribeathe ccm-A bination with a barrel having a free rear end portion and bored for small calibre ammunition, an actuating member including a rear portion bored to receive the powder case of such ammunition, said actuating member also having a sleeve extending forwardly from said rear portion and tting slidably on the rear end of said barrel, gas-tight packing between the rear end of the barrel and said sleeve, saidsleeve having gas-3 venting means closed when the sleeve is in ammunition ring position and open upon the sleeve moving a predetermined distance rearwardly, and bolt mechanism actuated by the rearward motion of said actuating member.

14. In a gun of the kind described, the combination with `a barrel having a free rear end portion and bored for small calibre ammunition, an actuating member including a rear portion bored to receive the powder case of such ammunition, said, actuating member also having a sleeve extending forwardly from said rear portion and fitting slidably on the rear end of said barrel, said sleeve having its inner face provided with a series of grooves extending from its open forward end to points spaced from its rear portion, the rearward movement of the sleeve being suiiicient to uncover the rear ends of said grooves, and vbolt mechanism actuated by the rearward motion of vsaid actuating member.

15. In a gun of the kind dascribed, the combination with a barrel having a free rear end portion and .bored for small calibre ammunition, an actuating member including. a rear portion bored to receive the powder case of such ammunition, said actuating member also having a sleeve extending forwardly from said rear portion and fitting slidably on the rear end of said barrel, gas-tight packing between the rear end of the barrel and said sleeve, said sleeve having its inner face provided with a series of grooves extending from its open forward end to points spaced from its rear portion, the rearward movement of the sleeve being suficienty to uncover the rear ends of said grooves, and .bolt mechanism actuated by the rearward motion of said actuating member.

16. In a gun of the kind described, the combination with a barrel having a free rear end portion and bored for small calibre ammunition,

an actuating member'including a rear portionbored to receive the powder case of such ammunition, said actuating member also having Aa sleeve extending forwardly from said rear portion and fitting slidably on the rear end of said barrel, said sleeve having gas-venting means closed when the sleeve is in ammunition-firing position, and open after the sleeve has moved a predetermined distance rearwardly, bolt mechanism means actuated by the rearward motion of said actuating member, and a cylinder surrounding the barrel andA sleevein spaced relation thereto and having the barrel secured in its forward end, said cylinder having its rear end open,

17. In a gun of the kind described, the combination with a barrel having a free rear end portion and bored for small calibre ammunition, an'actu'- ating member including a rear portion bored to receive the powder case of such ammunition.,l said actuating member also having a sleeve extending forwardly from said rear portion and fitting slidably on the rear end of said barrel, gas-tight packing between the rear end of the barrel and said sleeve, said sleeve having gas-venting means closed when the sleeve is in ammunition-firing position and open after the sleeve has moved a predetermined distance rearwardly, bolt mechanism actuated by the rearward motion of said actuating member, and a cylinder surrounding the barrel and sleeve 4in spaced relation thereto and having'the barrel secured in its forward end, saidcylinderhavin'g its rear end open.

18`. VIii-'a gunof the kind described, the combinationf with a barrel having a freerear end portion and bored for small ca-.libreammunitiom an actuating member including ya' rear portion bored to receive the powder case of such ammunitio'msaid actuating member also' having, a sleeve extending z forwardly from said rear portion and fitting slidably'on the rear end of said barrel, said sleeve having its inner face provided with a series of grooves extending from its openforward end to points spaced from its rear portion, the'rearward movement of the sleevebeing surlcient to. un

cover the rearl ends ofsaid grooves, bolt mechanism actuated -by the rearward motion of said 'actuatingmemben and a cylinder surrounding an `lactuating member including a rear portion bored to receive the powder case of such ammunition, said actuating member also having a sleeve extending forwardly from said rear portion and fitting slidably on the rear end of said barrel, gastight packing between the rear end of the barrel and said sleeve, said sleeve having its inner face provided with a series of grooves extending from its open forward end to points spaced from its rear portion, `the rearward -movement of the sleeve being sufficient to uncover the rear `ends of said grooves, bolt mechanism actuated by the rearward motion of said actuating member, and a cylinder surrounding the barrel and sleeve in spaced relation thereto and having the barrel secured in its forward end, said cylinder having its rear end open.

20. In a firearm, the combination of a barrel, a bolt mechanismtactuating member, a. powder case chamber cooperating with said actuator, said powder case chamber having a length shorter than the length of the powder case of the cartridge to be used therein, cooking means actuated by the rearward motion of said actuating member, a cartridge in said chamber having the forward end of its powder case projecting forwardly of said chamber and into the rear end of the barrel, the latter being recessed to receive the projecting end of the powder case, said recess having a chamfered peripheral wall to permit equalization of the gas pressure inside and outside of said projecting end. y

21. In a gun of the kind described, the combination with a barrel havingv a free rear end portion and bored for small calibre ammunition, an actuating member including a rear portion bored to receive the powder case of such ammunition, said actuating member also having a sleeve extending forwardly from said rear portion and tting slidably on the rear end of said barrel, bolt mechanism actuated by the rearward motion of said actuating member, the rear portion of the actuating member being proportioned to permit the forward end of a powder case to project therefrom, the rear end of the barrel being recessed tion with a barrel having a free rear end portiony and bored for small calibre ammunition, an actu- Asaid actuating member also having a sleeve extending forwardly from said rear portion and tting slidably on the rear end of said barrel, a gastight packing between the rear end of the barrelI and said sleeve, bolt mechanism actuated by the rearward motion of said actuating member, the rear portion of the actuating member being proportioned to permit the forward end of a powder case to project therefrom, the rear end of the barrel being recessed to receive thev projecting forward end of the powder case, said recess having a chamfered peripheral wall to permit equalization of the gas pressure inside and outside of said projecting end.

23. In a gun of the kind described, the combination with a barrel having a free rear end portion and bored for small calibre ammunition, an actuating memberincluding a rear portion' bored to receive the powder case of such ammunition, said actuating memberalso Ihaving a sleeve extending forwardly'from said rear portion and fitting slidably on the rear end ikof said barrel, said sleeve having gas-venting means'closed when the sleeve is in ammunition ring position, and open after the sleeve `has moved a predetermined distance rearwardly, bolt mechanism actuated by the rearward motion of said actuating member, the rear portion of the actuating member being proportioned to permit the forward end of a powder case to project therefrom, the rear end of the barrel being recessed to receive the projecting forward end of the powder case, said recess having a chamfered peripheral Wall to permit equalization of the -gas pressure inside and outside of said projecting end.

24. In a gun'of the kind described, the combination with a barrel having a free rear end por- .tion andbored for small calibre ammunition, an

actuating member including a rear portion bored to receive the powder case of such ammunition, said actuating member also having a sleeve extending forwardly from saidrear portion and itting slidably on the rear end of said barrel, gastight packing between the rear end of the barrel and said sleeve, said sleeve having gas-venting means closedwhen the sleeve is in ammunitionfiring position` and open after the sleeve has moved a predetermined distance reawardly, bolt mechanism actuated by the rearward motion of said actuating member, the rear portion of the actuating member being proportioned to permit the forward end of a powder case to project therefrom, the rear`end of the barrel being recessed to receive the projecting forward end of the powder case, said recess having a chamfered peripheral wall to permit equalization of the gas pressure inside and outside of said projecting end.

25. In a gun of the kind described, the combiy nation .with a barrel having a free rear end portion and bored for small calibre ammunition, ani

22. In a gun of the kind described, the combina- Cil actuating member including a rear portion bored` to receive the powder case of such ammunition,

said actuating member also having a sleeve extending forwardly from said rear portion and fitting slidably on the rear end of said barrel, said sleeve having its inner face provided with a series of grooves extending from.its open forward end to points spaced from its rearl portion, the

rearward movement of the sleeve being sumcient i to uncover the rear ends of said grooves, bolt `mechanism actuated bythe rearward motion of said actuating member, the rear portion of the i actuating member being proportioned to permit IIJ the forward end of a powder case to project therefrom, the rear end of the barrel being recessed to receive the projecting forward en d of the powder case, said recess having a chamfered peripheral Wall to permit equalization of the gas pressure inside and outside of said projecting end. 26. In a gun of the kind described, the combination with a barrel having a free rear end portion and bored for small calibre ammunition, an actuating member including a rear portion bored toreceive the powder case of such ammunition, said actuating member also having 'a sleeve extending forwardlyfrom said rear portion and fitting slidably on the rear end of said barrel, gastightpacking between the rear end of the barrel and said sleeve, said sleeve having its inner face provided with a series of grooves extending from its open forward end to points spaced from its rear portion, the rearward movement of the sleeve being sufficient to uncover the rear ends of said grooves, bolt mechanism actuated by the rearward motion of said actuating member, the rear portion of the actuating member being proportioned to permit the forward end of a powdercase to project therefrom, the rear'end of the barrel being recessed to receive the projecting forward end of the powdercase, said recess having a cham- ,f

feredv peripheral wall to permit equalization of the gas pressure inside and outside of said projecting end.

27. In a gun of the kind described, the' combi- -`nation with a barrel having a free rear end portion and bored for small calibre ammunition, an actuating member including a rear portion bored to receive 4the powder case of such ammunition, said actuating member also having a sleeve extending forwardly from said rear portion and itting slidably on the rear 4end of said barrel, said sleeve having gas-venting means closed when the 4 secured in its forward end, said cylinder having its rear end open, the rear portion of the actuating member being proportioned topermit the forward end of a powder case to project therefrom; the rear end of the barrel being recessed to receive the projecting forward end of the powder case,

said recess having a chamfered peripheral wall to` permit equalization of the gas pressure inside and outside of said projecting end.

28. In a gun of the kind described, the combination lwith a barrel having a free'rear end portion and bored for small calibre ammunition, an actuating member including a rear portion bored to receive the powder case of such ammunition, said actuating member also having a sleeve extending forwardly from said rear portion and tting slidably on the rear end of said barrel, gas-tight packing between the rear end of the barrel and said sleeve, said sleeve having gas-venting means closed when the sleeve is in ammunition firing position and open upon the.l sleeve moving a predetermined distance rear` wardly, bolt mechanism actuated bythe rearward motion cf saidI actuating mmbersand a cylinder surrounding the barrel and `sleeve in spaced relation thereto and `having they barrel secured in its `forward end, said cylinder having its rear end open, the rear portion of the actuating member being proportioned to. permit the forward end of a powder case to project therefrom, the rear end of the barrel being recessed to receive the lprojecting forward end of the powder case, said recess having a chamfered peripheral wall to permitequalization of the gas pressure inside and outsidevof said projecting end.

29. In a gun of the kindA described, the combination with a barrel having a free rear end portion and bored for small calibre ammunition, an actuating member including a rear portion bored to receive the powder case of such ammunition, said actuating member also having a sleeve extending forwardly from said rear portion and fitting slidably on the rear end of saidbarrel, said sleeve having its inner face provided with a series of grooves extending from its open forward end to points 'spaced from its rear portion, the rearward movement of the sleeve being suflicient to uncover the rear ends of said grooves, bolt mechanism actuated by the rearward motion of said actuating member, and a cylinder surrounding the barrel and sleeve in spaced relation thereto and having the barrel secured in its forward end, said cylinder having its rear end open, the rear portion of the actuating member being proportioned to permit the forward end of a powder case to project therefrom, the rear end of the barrel being recessed to receive the projecting forward end of the powder case, said recess having a chamfered peripheral wall to permit equalization of the gas pressure inside and outside of said projecting end.

30. In a gun of the kind described, the combinationwith a barrel having a free rear end portion and bored for small calibre ammunition, an actuating member including a rear portion bored to receive the powder case of such ammunition, said actuating member also having a sleeve extending forwardly from said rear portion and fitting-slidably on the rear end of said barrel, gas-tight packing between the rear end of the barrel and said sleeve. said sleeve having its inner face provided with a series of grooves extending from its openforward end to points ,spaced from its rear portion, to the rearward movement of the sleeve being sufficient to uncover the rear ends of said grooves, bolt mechanism actuated by the rearward motion of said actuating member, a cylinder surrounding the barrel and sleeve in spaced relation thereto and having the barrel secured in its forward end, said cylinder having its rear end open, the rear portion of the actuating member being proportioned to permit the forward end of a powder case to project ltherefrom, the rear end of thev barrel being recessed to receive the projecting forward end of the powder case, said recess having a chamfered peripheral wall to permit equalization of the gas pressure -inside and outside of ,said projecting end.

31. In a machine gun having breech mechanism and ammunition feeding means of such weight and resistance as to normally require high intensity ammunition to' operate the same; the combination of a stationary barrel, bolt means including a bolt, a reciprocating actuator provided with means for chambering a low intensity cartridge, said actuator being provided with a gas chamber member and having a gas chamber formed therein, communicating with said cartridge chambering means, said gas chamber member being mounted in telescopic relationship with the rear portion of the barrel, a. gas con- 2,027,892 tact area in said gas chamber member to initiate movement of vthe actuator under the influence of the gas, the actuator initiating rearward movement of the bolt, the area of said gas contact surface being predetermined in accordance with the'resistance of the moving parts of the gun, the force required -to function said masses, and the working pressure generated by said low intensity cartridge so that when the said cartridge is fired, the explosion gases will react against said area to produce a force suiiicient to overcome the resistance of the moving parts and function said moving `parts as satisfactorily as if high intensity ammunition were used, and means in addition to the usual barrel bore for venting a portion of the expanding gases from said gas chamber after the reciprocating actuator has moved a predetermined distance rearwardly after firing of the machine gun whereby any tendency of the actuatorto freeze to the barrel is prevented.

32. In a machine gun having breech mechanism and ammunition feeding means of such weight and resistance as to normally require high intensity ammunition to operate the same; the combination of a stationary sub-calibre barrel, bolt means including a bolt, a reciprocating actuator provided with means for chambering a low intensity cartridge and having a gas chamber formed therein communicating with said cartridge chambering means, said gas chamber member being mounted in telescopic relationship with the rear portion of the barrel, a gas contact area in said gas chamber member to initiate movement of the actuator under the inuence of the gas, the actuator initiating rearward movevment of the bolt, the area of said gas contact surface being predetermined in accordance with the resistance of the moving parts of the gun, the force required to function said masses, and the working pressure generated by said low intensity cartridge so that when the said cartridge is red, the explosion gases will react against said area to produce a force suiicient to overcome the resistance of the moving parts and function said moving parts as satisfactorily as if high intensity ammunition were used, and means in addition to the usual barrel bore for venting a portion of the expanding gases from said gas chamber after the reciprocating actuator has moved a predetermined distance rearwardly after firing of the machine gun whereby any tendency of the actuator to freeze to the barrel is prevented.

33. In a machine, gun having breech mechanism and ammunition feeding means of such weight and resistance as to normally require high intensity ammunition to operate the same; the combination of a stationary barrel, bolt means including abolt, a reciprocating chambered actuator provided with a powder case chamber having a length shorter than the length of the powder case of the cartridge to be used 'therein and carrying a low intensity cartridge with the forward end of its powder case projecting from the actuator ammunition chamber, said actuator having a gas chamb'er member and a gas chamber formed therein communicating with the ammunition chamber of the reciprocating actuator, said gas chamber member being mounted in telescopic relationship with the rear portion of the barrel, a gas contact area in said gas chamber member to initiate movement of the actuator under the vinfluence of the gas, the actuator initiating rearward movement of the bolt, the area of said gas contact vsurface being predetermined in accordance with the resistance of the moving parts of the gun, the force required to function said masses, and the working pressure generated by said low intensity cartridge so that when said cartridge is fired, the explosion gases will react against said area to produce a` force suicient to overcome the resistance of the moving parts and function said moving parts as satisfactorily as if high intensity ammunition were used, and

means associated with the barrel and the powder case ammunition, chamber arranged to cause equalization of gas pressure within and without said projecting end of the powder case whereby any tendency of the actuator to freeze to the barrel is prevented.

34. In a machine gun having breech mechanism and ammunition feeding means of such weight and resistance as to normally require high intensity ammunition to operate the same; the combination of a stationary barrel, bolt means including a bolt, a reciprocating chambered actuator provided with a powder case chamber having a length shorter than the length of the powder case of the cartridge to be used therein and carrying a low intensity cartridge with the forward end of its powder case projecting from the actuator ammunition chamber, said actuator being provided with a gas chamber member and having a gas chamber formed therein communicating with the ammunition chamber of the reciprocating actuator, said gas chamber member being mounted in telescopic relationship with the rear portion of the barrel, a gas contact area in said gas chamber member to initiate movement of the actuator under the innuence of the gas, the actuator initiating rearward movement of the bolt, the area of said gas contact surface being predetermined in accordance with the resistance of the moving parts of the gun, the force required to function said masses, and the working pressure generated by said low intensity cartridge so that when said cartridge is fired, the explosion gases will react against said area to produce a force sumcient to overcome the resistance of the moving parts and function said moving parts as satisfactorily as tance rearwardly after firing of the machine gun whereby any tendency of the actuator to freeze to the barrel is prevented.

DAVID M. WILLIAMS. 

